Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

Define obesity - excessive fat intake, Define Obesity - Excessive Fat Intak...

Define Obesity - Excessive Fat Intake? In obesity, cutting down total energy intake or increasing output to ensure energy balance is the basic principle of prevention. Fat bein

Meat product quality assurance, P r o d u c t Quality Assurance M...

P r o d u c t Quality Assurance Meat products should be manufactured under strict hygiene and sanitary conditions to avoid public health risks and improve aesthetic appea

Chlamydiosis-clinical manifestations, Clinical manifestations Since the...

Clinical manifestations Since the disease due to Chlamydia involves many organs/systems, system-wise descriptions of clinical signs is described as under: Genital infectio

Minerals requirements for dyslipidemia, Q. Minerals requirements for dyslip...

Q. Minerals requirements for dyslipidemia? Minerals: The three most important minerals are chromium, zinc and magnesium. These minerals play a critical role in maintaining p

What is hemoglobin, What is hemoglobin? What is the inorganic element that ...

What is hemoglobin? What is the inorganic element that is fundamental in the composition of hemoglobin? Hemoglobin is the protein present in the blood responsible for the trans

Define nutritional support management for chemotherapy, Define Nutritional ...

Define Nutritional Support Management for chemotherapy? Antiemetics are used in the treatment of chemotherapy induced nausea and vomiting. Antiemetics become absolutely necessa

Ammonotelism - excretion, Normal 0 false false false EN...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Define the antigen-presenting cells of the immune system, Q. What are the a...

Q. What are the antigen-presenting cells of the immune system? The antigen-presenting cells of the immune system also known as APC cells are cells that do digestion and phagocy

How are inhalation and expiration carried out, Q. How are inhalation and ex...

Q. How are inhalation and expiration carried out? The diaphragm exclusive of mammals and the intercostals muscles can contract or relax varying the volume of the thorax the com

Chordata.., write the classification of chordata?

write the classification of chordata?

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd